1. Field of the Invention
The present invention relates generally to the thermal dissipation of the ball screw and more particularly, to a ball screw capable of thermal dissipation based on a thermoelectric cooler.
2. Description of the Related Art
Balls moving inside a ball screw are very sensitive to temperature rise and when the temperature rise reaches 20° C. locally, the inaccuracy of one-meter stroke of the ball rod may reach 100 μm frequently. As the moving speed is higher, the noise and thermal energy may become greater to result in adverse effect on the working environment and the positioning precision. For this reason, the thermal energy generated while the ball screw is working needs to be dissipated.
Taiwan Patent No. I287073 disclosed that a cooling channel is applied to a ball screw; namely, the cooling channel is created around the screw nut to take away the heat generated in operation by liquid circulation to reach the purposes of cooling and precise positioning.
Taiwan Patent No. I300375 disclosed a cooling device for a ball screw, in which a flow channel runs through a central axis of the screw rod and a propeller is mounted inside the flow channel for generating spiral agitation to make the cooling liquid moving forward. In this way, the cooling effect can be boosted to further enhance the service life and precision of the ball screw.
Taiwan Patent No. M323540 disclosed a lubricating cooling system for a ball screw, in which the cooling device is an oil-mist supply system based on Venturi tube for atomizing the lubricating oil into oil mist and keeping supplying the lubrication and cooling among the ball screw, the screw rod, and the balls with the oil mist to further enhance the service life and precision of the ball screw.
However, all of the aforesaid patents adopted the cooling liquid or the oil to make the whole structures complicated to further make the processing and the assembly both uneasy and increase the size and weight of the ball screw. Thus, the aforesaid patents still need further improvement.